Make the dough: In a small bowl, combine yeast, sugar, and warm water. Let sit for 5–10 minutes until foamy. In a large bowl, mix flour and salt. Add yeast mixture and olive oil, stirring until dough forms. Knead on a floured surface for 5–7 minutes until smooth. Place in a lightly oiled bowl, cover, and let rise for 1 hour.

Preheat the oven: If using a pizza stone, preheat the oven to 475°F (245°C) with the stone inside for at least 30 minutes. If using a baking sheet, lightly grease it.

Cook the sausage and veggies: Heat 1 tablespoon olive oil in a skillet over medium heat. Add sausage and cook until browned, breaking it into crumbles. Remove and set aside. In the same skillet, add remaining oil, onions, and peppers. Cook for 6–8 minutes until softened. Season with salt and pepper.

Shape the dough: Punch down risen dough and roll it into a 12-inch circle. Transfer to parchment paper (for a stone) or directly onto a baking sheet.

Assemble the pizza: Spread pizza sauce evenly over the dough. Sprinkle with half of the mozzarella. Add sausage, peppers, and onions. Top with remaining mozzarella. Sprinkle with oregano and red pepper flakes (if using).

Bake: Bake for 12–15 minutes, or until crust is golden and cheese is bubbling.

Serve: Remove from oven, garnish with fresh basil, slice, and serve hot.